<%@ page import="java.util.ArrayList" %>
<%@ page import="java.util.HashMap" %><%--
  Created by IntelliJ IDEA.
  User: LMY
  Date: 2025/6/21
  Time: 22:42
  To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
  <head>
      <title>empty运算</title>
  </head>
  <body>
  <%
    request.setAttribute("k1", null);
    request.setAttribute("k2", "");
    request.setAttribute("k3", new Object[]{});
    request.setAttribute("k4", new ArrayList());
    request.setAttribute("k5", new HashMap());
  %>
  k1是否为空= ${empty k1}<br/>
  k2是否为空= ${empty k2}<br/>
  k3是否为空= ${empty k3}<br/>
  k4是否为空= ${empty k4}<br/>
  k5是否为空= ${empty k5}<br/>

  </body>
</html>
